The problem with fallibilism is that it is not well understood. Well, there I’ve said it, so why bother going on with this piece? Well I want to attempt to understand why exactly this simple idea is deceptively simple and therefore so easily mistaken for something else. Moreover many who claim to be fallibilists of some kind often turn out to be dogmatists of another kind which means they never were (thoroughgoing) fallibilists to begin with. I don’t like labels - I’d prefer they not be applied to people and instead reserved for ideas as a matter of convenience. Persons are not defined by their ideas but rather the capacity to create them in the first place. Labels tend to negate whatever else a person might say on the topic once you think they are a “rationalist” of some kind, for example. Even the bright and cheery “optimist” label has become a little “cliquey” of late but more importantly it too is too easily misunderstood. “I endorse optimism in David Deutsch’s sense of the word”, I prefer to say rather than answering to “I’m an optimist!” like some yellow pilled cultist with a big silly grin. But fallibilist? Well I don’t much mind admitting I might be wrong and indeed to be accused of as such is never an insult. Even about fallibilism. We will come to that. So call me fallible. I don’t much go in for those “pilled” things though I’ve already mentioned yellow pilled (I don’t know if that is already a thing) but if fallibilism was to be “pilled” I guess it’d be pink. Is it a colour? Isn’t it? It’s not on the rainbow. It’s negative green as some physicists have joked:  https://www.youtube.com/watch?v=S9dqJRyk0YM

Pink is a kind of mysterious colour. Is it a boy’s colour or a girl’s colour? At one point it was a boy’s (or at least considered “masculine”) now it’s a girl’s https://edition.cnn.com/2018/01/12/health/colorscope-pink-boy-girl-gender/index.html Of course with what I guess can only be called the 2020s “Gender Wars” the meaning of pink is once again up in the air.  So if a butch man thinks a pink shirt is just divine is he or isn’t he…you get my meaning. It’s all questions. Get pink pilled.

I tweet now and again that one way to think about fallibilism is simply the stance that “It is always possible to be wrong because there is something to be wrong about”. Very few people are thoroughgoing fallibilists. Even fewer than that recognise fallibilism in others.

The issue is that most people are either dogmatists (at least about something or other) or relativists (increasingly and sometimes even the same people on other issues).

Dogmatism is the misconception there exists something (usually many things, for a dogmatist) about which it is impossible to be mistaken. What is often held aloft are things like “1+1=2”. Pythagoras’ theorem. Everything in mathematics. Much of science. Or, of course, in a conversation with a sufficiently adept fallibilist the dogmatist will retreat like George Custer to the philosophical equivalent of Little Bighorn River: “I think, I exist” - Descartes’ cogito. Their last stand. They think that because they think then they are entitled to assert that it is absolutely certain and impossible to be mistaken at least on that point - they exist. They cannot imagine how it could be otherwise and so their lack of imagination on this point is somehow proof, in their minds, of truth. But why is it important for people to be absolutely certain they are in possession of a final truth? Isn’t simply knowing you exist enough? 
Brett, why does the distinction matter anyway? Who cares about the difference between “knowing” and “possessing certain truth”?
It matters deeply for two reasons. (1) Dogmatism everywhere is dangerous and as Popper admonished “The doctrine that the truth is manifest is the root of all tyranny” and (2) because only fallibilism always allows the possibility of infinite progress via continuous error correction.
Admitting you can always be wrong (even about fallibilism) means that there is always more left to learn and understand. When it comes to “I think therefore I am” or just “I exist” as being a statement - indeed logical proposition one can utter as some kind of necessary truth about which one cannot possibly be mistaken - it can be difficult for people to doubt this. They desire a foundation and, following Descates thing “Well this is it! The foundation! I am certain I exist!”
But a fallibilist needs no such foundation. They can pursue instead conjectural knowledge. On this I agree with Descartes: “I exist”. I can say that honestly. There’s no problem here. I can even add, rather unnecessarily, “I know I exist”. That’s enough for me. So rather than say “it cannot possibly be false that I exist” or even “I am certain I exist” I just say “I know I exist”. Or even “I exist”. Just not infallibly. Because I’m not infallible. About anything. Including “I exist”. I can improve my understanding of “I exist” and correct errors in what I think about it. I might not know right now how to improve it, but that is true of almost everything I know so there’s nothing special about that. And much of what we know like “I exist” contains inexplicit content too. Like what “exist” means or what “I” means and so on and on. Much about any claim when you dig deep is inexplicit. Indeed an infinite amount of inexplicit content lies there in an infinite potential well of inexplicit possibility. This infinite depth of the possibility for further understanding underscores the possibility of progress: the possibility for improvement. Optimism. 
I cannot say how it might be possible that “I exist” might be false - but this - my failure of imagination on that point - is no proof that it might nevertheless be false. I am a fallible human. There are many things I might be unable to imagine. Now having said all of this, especially saying all of this clearly and indeed coherently and even sometimes passionately then the criticism comes: well you sound terribly dogmatic. Which of course comes down to tone. Or not even tone but rather perceived tone. It’s like homophobia - one doesn’t actually need to be homosexual to experience homophobia. One only has to be perceived to be homosexual. And so too with dogmatism. The thoroughgoing fallibilist holds the position that all dogmatism is wrong is accused then of defending a dogma…about how all dogmatism is wrong. But that is simply a misconception to do with playing word games and trying to hold the fallibilist to the meanings of terms and explanations that the dogmatist insists on.
When I say “this is how it is: fallibilism is the only reasonable stance to take” - people think this is somehow self refuting. Indeed any time one explains any theory at all: matter is made of atoms. Or “I know that evolution by natural selection explains the diversity of species” or “The Big Bang happened” - people throw accusations of dogmatism around. “I know we people are universal explainers” really gets people’s backs up - especially in these times of discussions around AGI and AI. “You can’t know that! Dogmatism! You’re refusing to consider the alternative!” come the accusations thick and fast.
Let us linger on this related point for just a moment. Those who object to the claim “people can understand anything in principle” are arguing for a kind of anti-human alternative that…human beings cannot, even in principle, understand some things? 

And yet I, like everyone else in history, has been steeped in that lesson - that people are rather pathetic creatures. I know the argument well. Here let me make the case:

Our memories are limited.
Our brains are finite.
We just cannot comprehend somethings. 
You, Brett, don’t even understand the Korean language and yet you claim to have tried! 
If you’re a universal explainer find the successor theory to quantum theory right now! You see? You’re not a universal explainer! I’ve just told you two things you cannot understand or do. You’re just dogmatically committed to a faith claim.

But all of that is to ignore the explanation offered elsewhere about all this. I know the retorts and objections. It takes time to appreciate the power of universality - what a deep shift in perspective it takes to appreciate this relationship between what a person is, how they explain and understand by generating models in their mind of anything else in physical reality and that physical reality itself. How, as David Deutsch explains in his TED talk: the one structure comes to resemble the other: the mind and whatever in physical reality it is explaining.

But if one does explain all that and says “that’s the way it is” because that is what we know and we know that because it literally follows from our rational understanding of the world (we reject the supernatural) and…the accusations of dogmatism flow.

Stating “It just is the case that X. We know X. And we know X because our best explanation of science - quantum theory - implies X. Or our best theory of epistemology - conjectural knowledge growth - implies X” is not dogmatic. All those claims might be false. For a fallibilist that goes without saying. 

Of course when you do say it, as a fallibilist, the criticism flips. A moment ago the interlocutor accusing you of dogmatism now says “Oh, so you think nothing is actually true?! Relativist!”

This is the experience of the fallibilist. Stating as clearly as possible what we know and making the case with passion and curiosity and dare one say fun and excitement only to have that mistaken for dogmatism. At no point during what I sometimes call my “tirades” - which in truth are really just monologue summaries of explanations about exciting parts of science and philosophy - do I ever presume it’s not possible that I’m wrong. I could always be wrong. But how tedious would that become to add that caveat after every claim?

And as I say, having just made the exciting case for some bit of science or philosophy and being accused of dogmatism and so adding the caveat “no, I can always be wrong because of the universal fallibility of the process of knowledge creation” you are accused of relativism.  All this is because the only frame many have is: either you’re certain of certain truths (dogmatic in some sense as they are)…or you’re untethered to these foundational truths of reality entirely and you’re a relativist.

This is the problem with fallibilism. It’s very poorly understood. But that should be expected because we’re all fallible. All is a woven web of guesses.

Note that this post is focussed largely on science and how it works.

If you think that it is possible to accumulate evidence for a theory then a red pen is evidence in favour of the claim “all swans are white”. How is this so? And, Brett, aren’t you one of those people who keeps on saying you cannot have evidence for a theory anyway? Yes, I am. But let’s understand the reasons against this claim at a deeper level than some realise.

It’s not enough to know falsification works - that the existence of one black swan refutes “All swans are white”. You have to also know why the alternative perspective - almost universally subscribed outside of what is called “critical rationalism” is false. It needs to somehow become a deep part of your thinking that *positive evidence* just is not a thing and never can be. Which is to say you cannot have evidence for a theory; evidence that supports a theory or makes it more likely to be true and so on. That is not only unnecessary but it is absurd and let us see why momentarily. Let us first recap why it’s unnecessary. 

Once you have an explanation of the evidence, it no longer cries out for “support me” because there are no alternative theories. There’s just the one - the explanation. But, ok, imagine you’re in the rare position of having two good explanation. Well then if you find yourself in that rare position of having two or more good explanations then the function of evidence is to decide between those theories already guessed. When evidence does this it also serves the simultaneous purpose of serving as the so called “explicandum”: the thing to be explained. The explanation is there to explain the evidence. The evidence is there to decide between explanations. Ok, so all of that means “evidence in support” of a theory is unnecessary. But why is it also absurd?

Now we shall take a little lesson in logic. Consider if you like the claim “All swans are white” - so often held up as the pedestrian example of either “how falsification works” (find the unexpected - a black swan in other words, or maybe a translucent one these days) or as a way of teasing out exactly what Bayesian “epistemology” is trying to get at. How many swans need to be observed before we can say it’s “probably the case all swans are white”? Or likely? What is the threshold? And once you do employ Bayes’ theorem (that almost never happens, by the way: what is called “Bayesianism” never much involves Bayes’ theorem being actually deployed) - say you “update your initial prior probability in light of more white swans to 85% confidence that “All swans are white”) well then you can conclude, with something less than certainty, that “All swans are white”. Of course how certain you are that the 85% is 100% correct no one can say. 

But let us put aside all of those concerns about how many white swans need to be observed before concluding “all swans are white” - put aside that no finite list of observations (like seeing one millions swans) can never logically be equivalent to a universal claim about “All” anythings -  and let us even put aside science is not about making claims like “all swans are white” in the first place (it’s about explaining the world). 

All that aside. The idea that one can have “evidence in support” of a theory or claim like “All swans are white” by finding ever more white swans is logically equivalent to my looking on my desk any seeing any random thing there - like a red pen as also evidence in support of “All swans are white”.

If that seems absurd to you, it is. But this is one of the counter intuitive things about logic and one of the absurd consequences of the “evidence can support a theory” account of how science functions. It is a problem for that idea - but not a problem for falsification or explanation. What on Earth am I talking about?

The red pen on my desk is…a non white non swan.

“All swans are white” is logically equivalent to: “all non-white things are not-swans”. (In formal logic this is known as the “contrapositive”).

So given this rock solid logical fact of reality, anything at all in the universe you can point to that is not a swan and isn’t white is evidence in favour of “all swans are white” if you think there is such a thing as evidence in favour or support of any claim at all. So on the inductivist or Bayesian account of things every time you observe non white non swans (basically everything in the universe) your confidence in your theory about the truth of “All swans are white” should increase precisely because it amounts to being evidence in support of your theory.

Do you see how absurd the inductive account of science is? Of Bayesianism? Of non-explanatory, falsifiable conjectural scientific knowledge?

Science does not consist of claims like “All swans are white”. It consists of explanations. Evidence cannot be used to support a theory. It serves only to decide between explanations already guessed.

No amount of gathering more evidence about the world allows us to extrapolate general truths about it. What we have are problems - that’s where we begin. Our ideas at times fail to account for what is out there in the world. In science to resolve this clash of ideas between what we think and what we observe we have to use our imaginations to conjecture - guess - into existence a new and better explanation. Once we’ve done that, once we can explain the “problematic observation” we have a solution. And once we have that, there’s no need to further support it because, it’s all we’ve got. It’s the solution. It’s the good explanation. 

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Credit to my lecturer at The University of New South Wales, Professor Michaelis Michael who, aside from being the only professor of logic I know to have a name which is itself a tautology (Michael is Michael) - was the lecturer I most admired. His lectures were always fun. He meandered through the luminaries of philosophy and his encounters with some of them and peculiar stories of their lives and his as well as diving very deep in the classes I took with him on formal logic. It was Michaelis who set us the challenge of proving the soundness and completeness of sentential logic for one assignment. Sometimes assignments can be fun - and that one I remember was. And it's him I credit for leaving our class one afternoon at the end of the lecture with the problem as to why, as he held his red white board marker up, it was “evidence in favour of the claim that all swans are white”. It was on the bus ride home I realised I had the answer. Of course next lecture so did many others. It was class of logic students after all.